Professor Murdoch Mitchison

Professor Murdoch Mitchison, who died on March 17 aged 88, was a zoologist
regarded as a world authority on cell reproduction in yeast; he was also the
academic adviser and mentor to Sir Paul Nurse, President of the Royal
Society and winner of the 2001 Nobel Prize for Medicine.

Professor Murdoch Mitchison

6:50PM BST 05 Apr 2011

The titles of some of Mitchison's many dozens of publications give an idea of the focus of his scientific interests: "The Mechanical Properties of the Cell Surface"; "The status of haemoglobin in sickle-cell anaemia"; "The mechanism of cleavage in animal cells"; and "Differentiation in the Cell Cycle".

But it was for his work on the so-called fission yeast Schizosaccharomyces pombe (S. pombe), derived from ascomycetous fungi, that he was chiefly known.

In the early 1950s, around about the time Crick and Watson were examining the structure of DNA, Mitchison developed S. pombe as a "model organism" (a non-human species that is extensively studied to understand particular biological phenomena and to provide insight into the workings of other organisms). As fungi share a common ancestor with the animal kingdom, he reasoned that much of basic cell biology observed in S. pombe would also be relevant for basic mechanisms at work in animal cells.

Mitchison wanted to study the mechanisms and kinetics of growth and reproduction, since dividing cells usually have to grow before they can divide again. The rod-shaped cells of S. pombe were ideal because, as their diameters remain constant, he could simply measure increments in length in the cell cultures, following single cells in time-lapse photographs, or studying cultures in bulk.

His research resulted in the publication of his classic volume, The Biology Of The Cell Cycle, in 1971, five years after he had been elected a Fellow of the Royal Society of Edinburgh. He was elected a Fellow of the Royal Society of London in 1978.

In the early 1970s Paul Nurse successfully merged Mitchison's cell cycle work with genetic tools and methods developed by the Swiss scientist Urs Leopold to identify the gene in S. pombe which controls the progression of the cell cycle and cell division.

Later Nurse would identify the equivalent gene in the human genome.

Nurse has described the six years he spent as a postgraduate student with Mitchison in Edinburgh as "pivotal" for his entire research career: "He gave me both complete support and total freedom, spending hours each week talking with me but never instructing me what to do," Nurse recalled. "An astonishingly generous supervisor, he never once was a co-author on any of the papers I produced during my time in Edinburgh. He considered, quite wrongly of course, that he had not made a sufficient contribution to justify inclusion."

One of five children, John Murdoch Mitchison was born on June 11 1922 in Oxford, the son of GR "Dick" Mitchison, a barrister who would serve as Labour MP for Kettering during the 1960s, and the novelist Naomi Mitchison. His maternal grandfather was the Edinburgh physiologist John Scott Haldane, co-founder of the Journal of Hygiene, while an uncle was the geneticist JBS Haldane. His siblings, too, would achieve eminence in their own fields – his older brother Denis became a Professor of Bacteriology, while his younger brother Avrion is a leading immunologist. His sister Lois became an eminent sinologist, and his sister Val a radio critic and columnist.

Murdoch was educated at Winchester College, where he was a scholar, and Trinity College, Cambridge. He embarked on a medical degree, but decided to concentrate on Zoology after becoming disenchanted with Anatomy – the conclusive moment came when he had to root around in a bucket full of limbs to find an arm he was supposed to dissect. He went on to gain First-class honours in both Parts I and II.

Called up in 1941, Mitchison worked in Army Operational Research. Among the weapon systems he studied was a whole range of "funnies" – modified tanks equipped with unusual equipment such as flails, flame-throwers or propellers; he delighted in throwing cold water on some truly bizarre ideas, such as hundreds of arclight-generating tanks flickering all in synchrony, supposedly to demoralise the enemy. He then trained as an officer, becoming a lieutenant aged 21 and captain at 22. He served with the Eighth Army in Italy where his job involved analysing mud in the rice fields of Piedmont to see whether it was safe for tanks to roll through.

After the German surrender he recalled helping to liberate a small town in the Veneto where, during an impromptu street party, he danced with the female "capa" of the local partisans, who had live grenades round her belt.

Demobbed in 1946 in the rank of major, Mitchison returned to Trinity, where he became a research scholar then a fellow. In 1953 he moved to Edinburgh University as a lecturer and later reader in Zoology.

In 1947 he married Rosalind Wrong, a historian who would become the foremost authority on the social history of Scotland and expert on the Poor Laws.

Mitchison was Professor of Zoology at Edinburgh for 25 years, from 1963 to 1988, a member of the university court for several years and Dean of the Science Faculty in 1984-1985.

He also spent a decade as chairman of the university's major buildings committee, in which capacity he designed the planting around many new buildings.

His interests extended far beyond his own scientific field, and he was never content to be a merely passive recipient of knowledge. An interest in architecture led him to design his own house at Ormiston, East Lothian, and, when planning a beautiful garden there, he analysed soil samples to check that the land was suitable for the drifts of crocuses, azaleas and shrubs he wanted to plant. (Needless to say he knew all their Latin names). He was fascinated by human behaviour and history and at the end of his life was working on an account of the Italian campaign in which he had served.

Mitchison served as president of the British Society for Cell Biology from 1974 to 1977. He was also a member of the Royal Commission on Environmental Pollution and the Advisory Committee on Safety of Nuclear Installations.

Murdoch and Rosalind ("Rowy") Mitchison were keen travellers and walkers and generous hosts with a wide circle of friends. She died in 2002 and he is survived by a son and three daughters.